Cannot disconnect the device once it is connected

RE: Cannot disconnect the device once it is connected

Kyle Krueger — Thu, 21 Dec 2017 15:35:27 GMT

Only modifying it on disconnect could also be a problem. It should be modified on connect to update it. This way, in the case you make a connection, lose it, reestablish the connect, and try to end it manually, it may no longer have the correct handle.

RE: Cannot disconnect the device once it is connected

Joakim Jakobsen — Thu, 14 Dec 2017 08:40:58 GMT

Hard to say why it won't disconnect. Maybe you could upload your project so I can test it here?
Best regards.

RE: Cannot disconnect the device once it is connected

soma — Mon, 11 Dec 2017 15:59:24 GMT

I'm working with the SDK 11. I'm launching the disconnecting related code when I receive the event of a press button.

RE: Cannot disconnect the device once it is connected

Joakim Jakobsen — Tue, 05 Dec 2017 13:58:56 GMT

Which SDK example are you working with?
When do you make the call to the sd_ble_gap_disconnect()? Is it on a specific event that you want to disconnect?

RE: Cannot disconnect the device once it is connected

soma — Tue, 05 Dec 2017 13:50:06 GMT

yeah i'm sure that the device is connected. I even tried with the nrf toolbox and nrf connect application.

RE: Cannot disconnect the device once it is connected

Joakim Jakobsen — Tue, 05 Dec 2017 11:22:29 GMT

Hi Soma!

Are you sure that you are in a connection and that the connection handle has been updated before initiating the disconnect?
The error 0x3002 indicates that a invalid connection handle has been supplied.
I tested this in the ble_app_uart example in SDK 11, and it seems to work fine.
I executed the disconnection on a button push;

bool check; 
uint32_t err_code;
	case BSP_EVENT_KEY_2: 
	   check = softdevice_handler_isEnabled();
	   if ((check == true) && (m_conn_handle != BLE_CONN_HANDLE_INVALID))
	   {
	      err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
	      APP_ERROR_CHECK(err_code);
	   }
	   break;

The sd_ble_gap_disconnect() call initiates the disconnection procedure, and its completion will be communicated to the application with a BLE_GAP_EVT_DISCONNECTED event. Your connection handle will most likely be set to invalid when the disconnection event is received.
Take a look at this message sequence chart.

When the disconnection event i received, the device will most likely start advertising again.
You can see how this is handled in the ble_advertising.c file.
The fact that the sd_ble_gap_adv_stop() returns error code 0x0008 (NRF_ERROR_INVALID_STATE) is most probably because your device is not in advertising state yet.

Best regards,
Joakim.

RE: Cannot disconnect the device once it is connected

soma — Tue, 05 Dec 2017 09:05:06 GMT

Hi I use the SDK 11.0

RE: Cannot disconnect the device once it is connected

Joakim Jakobsen — Tue, 05 Dec 2017 08:38:27 GMT

Hi Soma!
Which SDK are you working with?

RE: Cannot disconnect the device once it is connected

soma — Mon, 04 Dec 2017 08:32:45 GMT

i tried doing it adding brackets to my statement but nothing changed. And I also tried to trace the modification of m_conn_handle but I only modify it after being disconnected

static void on_disconnect(ble_evt_t * p_ble_evt)
{
    uint32_t err_code;

    m_conn_handle = BLE_CONN_HANDLE_INVALID;

    // Stop timer if running
    m_update_count = 0; // Connection parameters updates should happen during every connection

    err_code = app_timer_stop(m_conn_params_timer_id);
    if ((err_code != NRF_SUCCESS) && (m_conn_params_config.error_handler != NULL))
    {
        m_conn_params_config.error_handler(err_code);
    }
}

here is the code where it is modifed

RE: Cannot disconnect the device once it is connected

Kyle Krueger — Wed, 29 Nov 2017 19:49:36 GMT

Maybe this question could also be helpful

RE: Cannot disconnect the device once it is connected

Kyle Krueger — Wed, 29 Nov 2017 18:57:58 GMT

Error 0x3002 means BLE_ERROR_INVALID_CONN_HANDLE, so it sounds like your validity check on m_conn_handle isn't working.

That makes the if statement suspect. I'd first recommend adding brackets to your if statement to separate the two logical comparisons.

if ((check == true) && (m_conn_handle != BLE_CONN_HANDLE_INVALID))

This makes sure the compiler knows the order to make the comparison in.

If that doesn't help, follow up on where m_conn_handle is last written, and post it here. Note that m_conn_handle can be invalid when it has other values than BLE_CONN_HANDLE_INVALID.

For example, the connection has already been once broken due to a poor signal, and m_conn_handle was not updated.